1.1 Weight & Thickness
GSM (Grams per Square Meter): The global standard for paper density.
Example: 80gsm (copy paper), 120gsm (magazine paper), 300gsm (business cards).
Point (pt): Thickness for 卡纸 /cardstock (1pt = 0.001" ≈ 0.025mm).
Common: 10pt (envelopes), 14pt (luxury packaging), 24pt (rigid boxes).
Fun Fact: A4 (210x297mm) 80gsm paper = ~5g per sheet – 200 sheets = 1kg.
1.2 Sizes
ISO Standards (Global):
A4 (most common), A5 (half A4), A3 (double A4).
Tip: A0 = 1m², each smaller size halves the longer side.
North American Sizes:
Letter (8.5x11"), Legal (8.5x14"), Tabloid (11x17").
Industry Use: Architects prefer ARCH sizes (ARCH A = 24x36"), while printers use SRA3 (320x450mm) for bleed margins.
1.3 Coatings
Uncoated: Matt finish, ideal for writing (e.g., 100gsm notebook paper).
Coated: Gloss/matte layers for vibrant prints (e.g., 150gsm brochures).
Specialty: Textured (linen, felt), metallic, or waterproof (e.g., food packaging).
2. Real-World Paper Types & Uses
2.1 Everyday Papers
Copy Paper (70-90gsm): Office work, drafts. Brands: HP Multipurpose, Double A.
Inkjet Paper (90-120gsm): High-absorbency for home printers (e.g., Canon Photo Paper).
Newsprint (45-55gsm): Thin, porous – perfect for newspapers (low cost, quick drying).
2.2 Creative & Professional Papers
Cardstock (160-400gsm): Business cards, invitations, greeting cards.
Pro Tip: 300gsm silk cardstock balances stiffness and print quality.
Watercolor Paper: Heavy (180-640gsm), rough texture – withstands wet media (e.g., Arches 300gsm).
Label Paper: Self-adhesive, coated for durable prints (e.g., shipping labels, wine labels).
2.3 Industrial & Packaging Papers
Kraft Paper (80-120gsm): Brown, strong – used for bags, boxes, and eco-friendly packaging.
Corrugated Cardboard: Layers of fluted paper + linerboard (e.g., 3-ply for Amazon boxes).
Grey Board (200-1000gsm): Rigid, cost-effective – book covers, luxury boxes (as used by Songhong Industrial).
3. Sustainability Trends
Recycled Paper: 30-100% post-consumer waste (PCW). Certifications: FSC, EU Ecolabel.
Tree-Free Alternatives: Bamboo (fast-growing), cotton (rag paper for currency), or elephant dung paper (yes, it's a thing!).
Carbon-Neutral Paper: Brands like "Paper One" offset emissions via reforestation projects.
Fun Fact: A single recycled A4 sheet saves 10L water and 15g CO₂.
4. How to Choose the Right Paper
Project Goal:
Printing: Coated paper for colors, uncoated for text.
Packaging: Strength (GSM/pt) > color – test drop resistance for fragile items.
Budget vs. Quality:
80gsm copy paper = $0.01/sheet; 300gsm art paper = $0.10/sheet.
Environmental Impact: Look for FSC-certified or recycled options (even 30% PCW makes a difference).
5. Myths vs. Facts
❌ Myth: "Thicker paper is always better."
✅ Fact: 120gsm coated paper may be smoother for photos than 200gsm uncoated.
❌ Myth: "All white papers are the same."
✅ Fact: "Bright white" (160+ whiteness index) enhances colors; "natural white" (80-90) reduces eye strain.
6. Industry Innovations
Digital Printing Papers: Designed for HP Indigo/VersaMark – instant drying, no smudging.
Edible Paper: Rice-based, used for cake decorations (FDA-approved).
Smart Paper: Embedded with NFC chips for interactive packaging (e.g., wine bottles linking to tasting notes).
Final Checklist for Buyers
✅ Know your size (A4? Custom? Bleed margins?).
✅ Specify GSM/pt and coating (gloss/matte/uncoated).
✅ Ask for samples – check texture, print quality, and durability.
✅ Prioritize sustainability – even small choices matter.
Whether you're printing a resume, designing a brand, or packing a gift, understanding paper basics ensures better results and smarter choices. Happy papering!